Add Borealis GUI for patch extraction on Switch.

Replace the console UI with a Borealis-based flow, bundle ROMFS assets and
borealis as a submodule, and apply small upstream patches at build time.
Self-delete runs after romfsExit on quit so the NRO can be removed like the
old console build.

source/extractor.hpp

@@ -0,0 +1,43 @@
+#pragma once
+
+#include <minizip/unzip.h>
+#include <string>
+
+class PatchExtractor {
+public:
+    static constexpr const char* PATCHES_ZIP  = "sdmc:/SaltySD/plugins/FPSLocker/patches.zip";
+    static constexpr const char* EXTRACT_DIR  = "sdmc:/SaltySD/plugins/FPSLocker/";
+    static constexpr const char* SELF_NRO     = "sdmc:/switch/PatchExtractor.nro";
+
+    bool open();
+    void close();
+
+    /** Process one zip entry. Returns false when finished or on fatal error. */
+    bool step();
+
+    bool isOpen() const { return zip != nullptr; }
+    unsigned long getTotal() const { return total; }
+    unsigned long getExtracted() const { return extracted; }
+    unsigned long getSkipped() const { return skipped; }
+    int getProgressPercent() const;
+    const std::string& getCurrentFile() const { return currentFile; }
+    bool isFinished() const { return finished; }
+
+    bool cleanup();
+    bool cleanupOk() const { return cleanupOk_; }
+
+    /** Call after the UI has shut down; releases romfs so the NRO file can be unlinked. */
+    static void tryDeleteSelfOnExit();
+
+private:
+    static int mkdirs(const char* path);
+
+    unzFile zip = nullptr;
+    unsigned long total = 0;
+    unsigned long extracted = 0;
+    unsigned long skipped = 0;
+    int err = UNZ_OK;
+    bool finished = false;
+    bool cleanupOk_ = true;
+    std::string currentFile;
+};